[runtime] Migrate several Date builtins to C++.

src/date.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_DATE_H_
 #define V8_DATE_H_
 
 #include "src/allocation.h"
 #include "src/base/platform/platform.h"
 #include "src/globals.h"
@@ skipping 172 matching lines @@
   }
 
   // Given the number of days since the epoch, computes
   // the corresponding year, month, and day.
   void YearMonthDayFromDays(int days, int* year, int* month, int* day);
 
   // Computes the number of days since the epoch for
   // the first day of the given month in the given year.
   int DaysFromYearMonth(int year, int month);
 
+  // Breaks down the time value.
+  void BreakDownTime(int64_t time_ms, int* year, int* month, int* day,
+                     int* weekday, int* hour, int* min, int* sec, int* ms);
+
   // Cache stamp is used for invalidating caches in JSDate.
   // We increment the stamp each time when the timezone information changes.
   // JSDate objects perform stamp check and invalidate their caches if
   // their saved stamp is not equal to the current stamp.
   Smi* stamp() { return stamp_; }
   void* stamp_address() { return &stamp_; }
 
   // These functions are virtual so that we can override them when testing.
   virtual int GetDaylightSavingsOffsetFromOS(int64_t time_sec) {
     double time_ms = static_cast<double>(time_sec * 1000);
@@ skipping 70 matching lines @@
   int ymd_month_;
   int ymd_day_;
 
   base::TimezoneCache* tz_cache_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif